Summary courtesy of ANN:
After losing their mother, Alphonse and Edward Elric attempt to bring her back using the forbidden science of human alchemy. However, alchemy operates on the theory of equivalent trade, and breaking the human alchemy taboo carries a heavy price. Ed loses his leg, and Al loses his life. Ed is able to seal Al?s soul inside of a huge suit of armor, at the cost of his arm. Years later, Ed (now with two mechanical limbs) and Al (still trapped in the armor) leave their childhood home, each brother concerned with the other?s happiness. They are searching for any information on the fabled Philosopher?s stone, hoping it will allow them to regain their old bodies. Ed, who has a natural talent and skill for alchemy, soon becomes nationally certified. He is soon known everywhere as the "Fullmetal Alchemist."
I only got to download a few of the episodes before peer-to-peer was banned at my college, but from what I saw and from the rave reviews around the internet, I'm really excited about FMA. It has its light moments, but when it's dark, it's dark.